They are not. You'll know a proof when you see one. And finding one in circulation, as I imagine you did those, is fairly rare. Compare them to another proof, the differences will be readily apparent.
They would have an S mintmark if proof for those years. Might I suggest investing in a Redbook, that would have that info in it.
Proof coins will have mirrored fields and frosty devices on modern issues. Also, the strike quality will be evident. The rims will be squared off and not rounded due to the extra strike pressure and the happenstance of the coin being struck more than once........
